containerd/vendor/github.com/crosbymichael/cgroups/prometheus/metrics.go

115 lines
2.8 KiB
Go

package prometheus
import (
"errors"
"strconv"
"sync"
"github.com/Sirupsen/logrus"
"github.com/crosbymichael/cgroups"
metrics "github.com/docker/go-metrics"
"github.com/prometheus/client_golang/prometheus"
)
var (
ErrAlreadyCollected = errors.New("cgroup is already being collected")
ErrCgroupNotExists = errors.New("cgroup does not exist in the collector")
)
// New registers the Collector with the provided namespace and returns it so
// that cgroups can be added for collection
func New(ns *metrics.Namespace) *Collector {
// add machine cpus and memory info
c := &Collector{
ns: ns,
cgroups: make(map[string]cgroups.Cgroup),
}
c.metrics = append(c.metrics, pidMetrics...)
c.metrics = append(c.metrics, cpuMetrics...)
c.metrics = append(c.metrics, memoryMetrics...)
c.metrics = append(c.metrics, hugetlbMetrics...)
c.metrics = append(c.metrics, blkioMetrics...)
ns.Add(c)
return c
}
// Collector provides the ability to collect container stats and export
// them in the prometheus format
type Collector struct {
mu sync.RWMutex
cgroups map[string]cgroups.Cgroup
ns *metrics.Namespace
metrics []*metric
}
func (c *Collector) Describe(ch chan<- *prometheus.Desc) {
for _, m := range c.metrics {
ch <- m.desc(c.ns)
}
}
func (c *Collector) Collect(ch chan<- prometheus.Metric) {
c.mu.RLock()
wg := &sync.WaitGroup{}
for id, cg := range c.cgroups {
wg.Add(1)
go c.collect(id, cg, ch, wg)
}
c.mu.RUnlock()
wg.Wait()
}
func (c *Collector) collect(id string, cg cgroups.Cgroup, ch chan<- prometheus.Metric, wg *sync.WaitGroup) {
defer wg.Done()
stats, err := cg.Stat(cgroups.IgnoreNotExist)
if err != nil {
logrus.WithError(err).Errorf("stat cgroup %s", id)
return
}
for _, m := range c.metrics {
m.collect(id, stats, c.ns, ch)
}
}
// Add adds the provided cgroup and id so that metrics are collected and exported
func (c *Collector) Add(id string, cg cgroups.Cgroup) error {
c.mu.Lock()
defer c.mu.Unlock()
if _, ok := c.cgroups[id]; ok {
return ErrAlreadyCollected
}
c.cgroups[id] = cg
return nil
}
// Get returns the cgroup that is being collected under the provided id
// returns ErrCgroupNotExists if the id is not being collected
func (c *Collector) Get(id string) (cgroups.Cgroup, error) {
c.mu.Lock()
defer c.mu.Unlock()
cg, ok := c.cgroups[id]
if !ok {
return nil, ErrCgroupNotExists
}
return cg, nil
}
// Remove removes the provided cgroup by id from the collector
func (c *Collector) Remove(id string) {
c.mu.Lock()
defer c.mu.Unlock()
delete(c.cgroups, id)
}
func blkioValues(l []cgroups.BlkioEntry) []value {
var out []value
for _, e := range l {
out = append(out, value{
v: float64(e.Value),
l: []string{e.Op, e.Device, strconv.FormatUint(e.Major, 10), strconv.FormatUint(e.Minor, 10)},
})
}
return out
}